Support for resonant sounding  tubes



Jan. 21, 1958 G. w. LESCHER 2,820,431-

SUPPORT FOR RESONANT SOUNDING' TUBES Filed Nov. 25, 1956 INVENTOR the conventional Xylophone, chimes, etc.

United States Patent SUPPORT FOR RESONANT SOUNDING TUBES George Wright Lescher, Hagerstown, Md. Application November 23, 1956, Serial No. 623,859

9 Claims. (Cl. 116-169) This invention relates to resonant sounding tubes and is directed in particular to novel means for supporting such tubes when clear resonant tones are desired, such as in musical chimes, organs, clock chimes, xylophones, door chimes, or any other musical instrument or sounding device in which such tubes might be employed.

Resonant sounding tubes have been-used previously in musical instruments and sounding devices of various types wherein a musical sound would be emitted by a tube when caused to resonate or vibrate at its natural frequency upon being struck a blow by a suitable striker. Although the type of musical sound emitted by the sounding tubes depends upon the material used, the length of the tube, the diameter and the wall thickness of the tube, the volume of the sound as well as the purity of its musical quality and its sound-duration quality are all largely determined by the method of mounting or supporting the tubes. The most desirable arrangement would be to mount such tubes in such manner as to allow them to vibrate at their natural frequency in as nearly a free-body condition as possible and at the same time support them in a device in which they are to be used in a sufficiently rigid condition to permit the device to be readily moved about and be positioned in various attitudes without having the tubes slip or slide about or collide with each other and at the same time provide a support that will not reduce the purity of tone of the tubes. The methods and structures thus far proposed for mounting or supporting such tubes have all fallen short of the most desirable arrangements by their simply providing for suspension from, resting on, or restrained by, cords, strings, threads, straps, or pins, in a more or less relatively unfixed manner as found in On the other hand, in those instances in which an attempt has been made to provide a relatively rigid mounting by clamping or tying the tube tightly to adjacent structure, a sacrifice has been made in the musical quality or purity of tone, volume of the radiated sound, and the duration of sounding time.

I have discovered that in order to achieve the most desirable characteristics the means used to mount the tube to adjacent structure should, firstly, touch the tube only at or quite near or in the immediate vicinity of the natural nodal points of the tube; secondly, the area of the material comprising the mounting means in contact with the tube should be at a minimum; and, thirdly, the area of the material in immediate contact with the tube should be of a resilient, soft or pliable nature. I have also discovered that aluminum is a material ideally suited for use as sounding tubes instead of brass which is frequently used for the purpose. if aluminum be used for the above stated purpose, it should be, preferably, of a hard variety or one of the alloys of aluminum. Such material is equally as good for the purpose as brass and at the same time is less expensive, considerably lighter in weight, and may be provided in a variety of colors through a treatment known in the art as color anodizing.

It is therefore a primary object of the present inven- ICC? tion to provide a means for supporting a sounding tube of the general type described herein in such manner as to permit the tube to vibrate at its natural frequency in as near a free-body condition as practicable when held in an external mounting structure, and to radiate at an optimum volume and with optimum purity and clarity of tone when caused to vibrate by being struck or otherwise set in vibratory motion by air, magnetic fields, electric fields, or other means.

It is also an object to obtain an optimum natural musical tone from and sustained over an optimum period of time by a vibrating sounding tube by providing a support for such tube which presents a minimum of contact surface and pressure, at optimum points on the tube, in order to apply a minimum distorting and damping effect on the practically freely-vibrating tube.

It is another object to support, hold, or restrain a sounding tube against any substantial lateral or longitudinal movement by means which are in contact with the tube only at or close to its natural nodal points, at which points the tubes natural vibration amplitude is at a minimum.

It is a further object to provide a means for prolonging the duration of audible tone of a sounding tube by providing a supporting means through which a minimum of the tubes vibration is transmitted to or through the base or external mounting element to which the tube supporting element is attached and by permitting the tube to act as its own sounding board to the maximum extent while dissipating to a minimum extent its vibratory energy to elements external to itself, such as a mounting base or an auxiliary sounding board.

it is a still further object to provide a means for supporting a. sounding tube in a relatively fixed manner with respect to the supporting element, that is, the tube is supported in such a manner as to allow only a predetermined, restricted amount of movement with respect to its supporting element.

It is another object to provide a means for supporting a sounding tube in a manner such that it may be positioned statically in a vertical attitude, a horizontal attitude, or any other attitude, or put in vibratory motion in a con stant attitude or in varying attitudes, without impairment of the characteristics achieved through the foregoing objectives.

It is still another object to provide support for a sounding tube to be effected substantially from inside the tube itself, rather than from outside, so as to permit close-r spacing of two or more tubes and to permit a more compact, more sturdy, more practical, more relatively rigid, better protected and more concealed, less exposed method of support for such tubes than the methods customarily employed.

I achieve the above objects in a manner as more particularly set forth herein and shown in the appended drawings in which:

Fig. 1 is a longitudinal view partly in section of a resonant sounding tube provided with one of the preferred forms of the present invention;

Fig. 2 is a view similar to Fig. l and illustrating the tube support in a different form as applied to a sound tube adapted to be held in the hand;

Fig. 3 is a longitudinal section view showing a different form of the invention applied to a sound tube primarily intended to be mounted in a horizontal position;

Fig. 4 is a view similar to Fig. 3 in which the tube support includes the use of a wire, cord, or other nonrigid material attached to external support members;

Fig. 5 is a section view taken on line 55 of Fig. l but in full cross-section showing one of the lateral restraining washers;

Fig. 6 is a section view taken on line 6-6 of Fig. 1 in 3 full cross-section showing one of the longitudinal restraining arrangements of the present invention;

Fig. 7 is a section view taken on line 77 of Fig. 4 in full cross-section showing a variation of washer construction wherein its shape is square to provide four sharp points that may touch the tube;

Fig. 8 is a fragmentary longitudinal view partly in section illustrating a longitudinal tube restrainer in the form of a tubular member flared at each end and a lateral tube restrainer formed integral with the longitudinal support;

Fig. 9 is a fragmentary longitudinal view partly in section of a longitudinal tube restrainer in the form of a screw coated with a resilient material; and

Fig. 10 is also a fragmentary longitudinal View partly insection of another modification of longitudinal tube restrainer wherein the restrainer is formed integral with the longitudinal support member.

Referring first to Fig. 1, there is illustrated a resonant sounding tube 10 which has two distinct node points of vibration. Centrally positioned within the tube lid is a longitudinal support member 13' which extends from the external structure base member 14 at one end of the tube 10- to a point at least beyond the upper nodal point of the. tube. Base 14 may be a part of a musical instrument, annunciator chime, a toy, or any other sound device. Although the member 13 is shown extending from only one end of the sound tube 10, it may of course extend from the other end also, as indicated by broken lines 15, to mount in external structure 16, also indicated by broken lines. I have found that the longitudinal member 13 may be. readily constructed from an ordinary wooden dowel althoughv other materials such as metal, plastic, etc. are quite satisfactory. The member 13 may be round, square, triangular, in cross section, and, in addition, may be solid or tubular- In order toprovide a means for the lateral restraining of'the sound tube 10, a pair of washers 17 and 18 are positioned on the longitudinal member 13, one at or very near the location of one of the nodal points of the sound tube 10 and one at or near the other nodal point. In this 4 connection, as used hereafter in this specification and in the appended claims, the expression at a nodal point shall be considered to include points within the general area of or substantially near the natural nodalpoint of the tube. These washers are preferably somewhat smaller than the inside diameter of the tube 1! in order that the fit between the tube and the Washers will be loose rather than snug. A clearance of between .01 and .03 inch has been found to be satisfactory. Also,- it is preferable that the area of the washer material that comes in contact with the inside of the tube 10 at any time shall be at a minimum. In order to accomplish this desirable condition, the lateral restraining washers may have an irregularily shaped edge, such as that shown in the section view in Fig. 5, wherein the edge is scalloped to provide a plurality of very narrow contact points 19 which may touch the inside wall of the tube'1'0. The shape of the washers may also be square, as shown in Fig. 7, triangular, star-shaped, or any other shape which will provide the desirable minimumacontact area betweenthe washer and tube.

In addition to the importance of providing a loose fit between the tube 10 and the lateral restraining washers 17 and 18, it has been found desirable, in order to obtain the optimum volume and quality of tone from the tube when resonating, that any material that touches the tube have a resilientquality. For this reason the washers are preferably fabricated of rubber or a rubber-like material, such as one of the resilient or soft-type plastics. It is, of course, possible to construct the lateral restraining washers. from a non-resilient material provided that there is a resilient meansof contact between the tube and washer. This can be accomplished. by coating the washer with a suitable resilient material as by dipping it in or spraying it with a liquid latex or one of the rubber-like plastics. While it is not necessary that the entire surface of the washer be coated, at least the contact points 19 should be coated with some resilient material. These restraining washers may be attached to the longitudinal member 13 in any suitable manner, as by glueing or cementing, but where the washer is fabricated of rubber or other such resilient material, it will be found quite satisfactory in most cases to provide a snug fit between the washer and the longitudinal member and rely upon the natural elasticity of the material to anchor the parts together.

Even though the longitudinal support member has been illustrated as being of substantially less diameter or less cross-section area than that of the sound tube 10, a longitudinal member having a diameter only slightly less than the inner diameter of the tube may be used as is shown in Fig. 8. In such case the lateral restraining means which I have referred to as washers may actually be rings of rubber or other resilient material and may be a simple rubber band. In cases such as that illustrated in Fig. 8, the lateral restraining means may also take the form of small projections or protuberances 20 which may be integral. with the longitudinal member 13. This construction' may be used particularly when the member 13 is molded from plastic, in which case it is relatively easy to cast the projections 20 integral therewith. It is important, however, that unless a resilient material is used in casting the member 13 and its projectionsv 20, a suitable resilient coating should be provided over the projections for contact with the tube 10.

In order to restrain the sound tube 10 in a longitudinal direction, openings 21, 22 are provided through the tube Walls at or near one of the nodepoints to receive a flexible cord, wire, or other non-rigid material 23 which also passes through a transverse opening 24 through the member 13. As shown inFig. 6 the endsof the cord are-loosely carriedaround the tube 10'and tied together, allowing just enough play to permit the tube to move slightly in a longitudinal direction. The amount of play need only be sufficient for the tube to freely vibrate but in any case the cord should not be tightly tied about the tube since it will tend to deaden the sound emitted by the tube. If a wire be used instead of a cord, it should be covered with a resilient coating such as, for example, the plastic rubberlike wire covering known in the electric wiring trade as spaghetti and if the wire selected for the purpose is sub stantially rigid it neednot' be wrapped about thetube and tied, or the ends twisted, but may be a much shorter straight piece with the ends crimped, looped, or bent after passing through the tube.

Referring next to Fig. 2, there is shown a sound tube in which is adapted to be held by hand and struck with a hammer (not shown) heldin the-other hand. In this case the longitudinal member 13, which may be a wooden dowel, extends from one end of the tube 10 and is suitably fixed to a handle 25' which may be conveniently grasped by the hand. Surrounding the dowel and attached thereto as by a rivet 26 is a combination longitudinal and lateral restraining member 27 which may be made of plastic or metal or any other material having some degree of springiness.

The member 27 is bifurcated at each end to provide a pair of flexible arms 28', 28 at one end, and flexible arms 29, 29 at the other end. Each pair of arms is spread outwardly to approach but not quite touch the inner walls of the tube 10, whereby suflicient space is provided between the longitudinal member 13 and the arms to allow the arms to be pressed inwardly for insertion into the tube during assembly. Each of the arms 28, 28' and 29, 29" is provided with a stud membe]: 3% which may be formed integral withthe arms and, in which case, are coated'with a suitable resilient material such as latex. The tube 10 ispr'ovided" witha pair of aligned holesv 31, 32 through the walls thereof at one of its nodal points and with aligned holes 33, 34 ,at its other nodal point, each to receive one of the four studs 34). Each of the four holes for receiving the studs should be somewhatlarger than the studs to provide a Preferably, the holes should be about twice the diameter of the studs.

rather loose fit therebetween.

In Fig. 3 is illustrated an arrangement for supporting the sound tube wherein a pair of longitudinal support members 35 and 36 are provided within the tube and which extend from the ends thereof to engage, respectively, the external support members 37 and 38. A lateral restraining washer 39 is attached to the longitudinal member 35 near its free end and is positioned at one nodal point while a second restraining washer 40 is similarly attached to the other longitudinal member 36 and is positioned at the tubes other nodal point. The restraining washer 39 is considerably thicker than those previously described and is shown as spool-shaped to receive an indented portion 41 of the tube 10. Although the tube is shown indented at only one place, it is obvious that it can be indented also at the opposite side, or in fact in a plurality of places around the tube, if desired. Also, although the longitudinal tube restraining means are illustrated as being used at only one of the two nodal points, they can, of course, be used at both nodal points by substituting the same type washer shown at 39 for the round, thin washer 40 and indenting the tube at the second nodal point in the same manner as at the first nodal point.

Figure 4 illustrates another embodiment of the invention in which a taut cord, or wire, or other tightly stretched non-rigid member 42 serves as the longitudinal support member and on which is mounted or to which is attached the lateral restraining washers 43 and 44. The longitudinal member 42 extends through the tube 10 from opposite ends thereof and is adapted in length for attachment to screw eyes 45 and 46 that threadably engage, respectively, external structure members 47 and 48. The longitudinal member 42 which, of course, may be a single piece of taut cord or wire, or other taut non-rigid material, is in the present embodiment composed of three pieces of cord or wire 49, 50, and 51. Cord 49 joints the two washers 43 and 44 while cord 50 joins the washer 43 with the screw eye 45, and cord 51 joins the Washer 44 with the other screw eye 46. Attachment of the cords or wires to the screw eyes and to suitable fittings on the washers may be accomplished by glueing or tying, it cord be used, and by twisting if wire be used.

In order to restrain the tube in a longitudinal direction, a pair of nails 52, 52' pass through openings 21 and 22, respectively, in the tube 10 and are driven into or cemented in or otherwise afiixed to the washer 43. As an alternate arrangement, screws may be used instead of nails or the washer may be provided with a hole in alignment with the holes in the tube and a cord or wire used in the same manner as shown in Fig. 1 to provide the longitudinal restraint. Although both the washers 43 and 44 may be of the same shape, in the present instance the washer 44 is square as shown in the section view Fig. 7.

Figures 8, 9, and 10 illustrate three difierent methods of restraining the tube 10 in a longitudinal direction. In Fig. 8, a tubular pin 53 passes through aligned holes 21 and 22 in the tube 10 and hole 54 in the support member 13, each of which holes is of substantially greater diameter than the pin 53. Pin 53 is flared at each end to loosely join the tube 10 with the support 13. In addition to the loose fit provided to allow slight movement between the tube and the support, it is preferable that the pin 53 be coated with a resilient material particularly if the pin be made of metal. The lateral tube restraining structure includes projections 20 that are integral with the support 13, such as have already been described in connection with Fig. 8.

Fig. 9 illustrates the use of a screw 55, coated with a suitable resilient material, passing through a hole 56 in tube 10 and threadably engaging the support member 13, which in the preferred form is a wooden dowel.

Lateral restraint may be provided by the washer 18.

Fig. 10 illustrates longitudinal restraining means comprising a projection or arm 57 formed integral with the support member 13 which, for example, may be molded from plastic material. The arm 57 passes through a hole 58 in the tube 10 at one of its nodal points. As in the case of the arrangements shown in Figs. 8 and 9, the hole 58 is somewhat larger than the arm 57 to assure a loose fit therebetween while at the same time restraining the tube and preventing any substantial movement of the tube in a longitudinal direction. A lateral restraining washer 18 is provided on the support 13 and adjacent to the arm 57 to prevent any substantial movement of the tube It in a lateral direction.

Although not shown in the drawings, the longitudinal restraining means illustrated may be dispensed with in certain cases wherein the sounding tube is mounted in a horizontal position and intended for operation in a horizontal position only as, for example, in a Xylophone type musical instrument. In Fig. 3 for instance, the indented portion 41 may be eliminated in which case the tube will slide on the two lateral restraining washers 39 and 40 in a longitudinal direction and limited in such movement only by abutting contact with the external members 37 and 38. In such case the members 37 and 38 should, preferably, be quite near each end of the tube 10 to provide a longitudinal restraining means externally of the tube to prevent any substantial movement or shifting of the tube longitudinally. The construction shown in Fig. 4 may also be used in the horizontal tube mounting arrangement in which case the longitudinal restraining nails 52, 52 may be omitted. The external mounting and restraining members 47 and 48 would then be positioned substantially close to the tube ends.

The invention has been shown in preferred forms only and by way of examples only, andobviously many variations and modifications may be made therein without departing from the spirit of the invention. For example, the longitudinal member 13 and the member 27 may be made in one piece by molding or otherwise. Also, the longitudinal member 13 and its washer 18 of Figure 1 may be combined with only the upper portion of member 27, the washer 18 then producing lateral restraint otherwise produced by the two arms 29, 29' at the lower end of member 27. The invention is, therefore, not to be limited to any specified form or embodiment except insofar as such limitations are set forth in the claims.

I claim:

1. A support for a resonant sounding tube having two nodal points comprising a longitudinal support member within said tube and extending from at least one end thereof, longitudinal restraining means on said support member resiliently engaging said tube at at least one of its nodal points and lateral restraining means on said support member resiliently engaging said tube at both said nodal points.

2. A support for a resonant sounding tube having two nodal points comprising a longitudinal support member within said tube and extending from both ends thereof, longitudinal restraining means on said support member resiliently engaging said tube at at least one of its nodal points to prevent any substantial movement of said tube in a longitudinal direction and lateral restraining means on said support member resiliently engaging said tube at both nodal points to prevent any substantial movement of said tube in a lateral direction.

3. A support for a resonant sounding tube having two nodal points comprising a pair of longitudinal support members within said tube each extending from an end thereof, longitudinal and lateral restraining means on one of said support members loosely engaging said tube at one of its nodal points and second lateral restraining means on the'other said support member-loosely engaging said tube" at its other nodal point.

4-. A support for a resonant sounding tube having two nodal'points comprising a firstlongitudinal support member Within said tube and extending from one end thereof, a second longitudinal support member Within said tube and extending from the opposite end thereof, a first lateral restraining'means on said first longitudinal support member resiliently engaging said tube at the first of its nodal points, a second lateral restraining means on said second longitudinal support member resiliently engaging said tube at its second nodal point, and longitudinal restraining' means integral with said tube loosely engaging at least one of said first and said second lateral restraining means.

5; A support for mounting a resonant sounding tube having two nodal points in a horizontal position comprising afirst longitudinal support member Within said tube and extendingfrom one end thereof, a second longitudinal support member Within said tube and extending from the other end thereof, lateral restraining means on said first longitudinal support member resiliently engaging said tube at one of said nodal points, second lateral restraining means on said second longitudinal support member engaging said tube' at the other said nodal point, a support structure exterior of said tube and adjacent one end thereof engaging one end of said first longitudinal support member, and a second support structure exterior of said tube and adjacent the other end thereof engaging one end of said second longitudinal support member whereby said tube is supported horizontally and limited in movement longitudinally by abutting against either of said exterior support members.

6; A support for a resonant sounding tube having two nodal points comprising tube supporting means Within said tube and extending from at least one end thereof, longitudinal tube restraining means associated with said supporting means and said tube for preventing substantial longitudinal movement of said tube and lateral restraining means on said supporting means loosely engaging said tube at both said nodal points for preventing substantial lateral movement of said tube.

7'. Ai-support for ii -resonant sounding tube iniaceord; auce with claim 6 wherein the said supporting. means: is a longitudinal: member extending. from the-ends of? said tube and the said longitudinal restraining means are two exterior members, one exterior member engaging; one end of said longitudinal member and positioned adjacent one: end of said tube and the other exterior member engaging the other end of said longitudinal member and positioned adjacent the other end of said tube.

8. A support for a resonant soundingv tube having two nodal points comprising tube supporting means within said tube and extending from at least one end thereof, a first lateral restraining Inember'connected to said supporting. means and loosely engaging said tube at oneof said nodal points, a' second lateral restraining member connected to said supporting means and loosely engaging said tube at the other said nodal point and a longitudinal restraining member onone of said first and second' lateral restraining members resiliently engaging said tnbeat a nodal point.

9. A support for a resonant sounding tube having two nodal points comprising a longitudinal supporting member within said. tube and extending from each end thereof, the said supporting member being of taut non-rigid material, lateral restraining means on said supporting memberloosely engaging said tube at each of the said two nodal points and longitudinal restraining means. associated with said supporting member and said tube at a nodal point for preventing substantial longitudinal movement of said tube.

References Cited in the file of this patent UNITED STATES PATENTS 

